1. Field of the Invention
This invention relates to an ink jet recording apparatus and a discharge recovery apparatus used in said apparatus.
2. Related Background Art
For a recording apparatus, which conventionally records on a recording medium (hereinafter called xe2x80x9crecording sheetxe2x80x9d or simply xe2x80x9cpaperxe2x80x9d) such as paper and sheet for OHP, forms of mounting a recording head using any of various recording methods have been proposed. This recording head has various methods such as wire dot, thermal, thermal transfer, and ink jet methods.
Especially the ink jet method directly jets ink on a recording sheet, and draws attention as a quiet recording method with low running cost.
In a recording apparatus using the ink jet method, a recording head, in which fine discharge ports have been arranged, is generally used. When air bubble or dust enters the discharge port, or when ink has become unsuitable for discharge or recording owing to thickening caused by evaporation, of ink solvent, etc., and the like, the state of discharge is maintained or recovered by the following: refreshing the ink by recovering the suction through the discharge port or by predischarging, or allowing some discharge ports, which are not concerned in discharge during recording, to discharge ink in order to maintain all discharge ports in a condition suitable for discharging always.
As a form of the means to maintain and recover the discharge, there is a recording apparatus provided with a cap member capable of covering the discharge port formation surface of the recording head, and with suction means such as pump means which communicates with this cap member and applies a suction force to the discharge port of the recording head.
The factor for improper discharge is removed together with the ink by discharging ink (predischarge, idle discharge) by driving an ink discharge energy generating element inside the discharge port while the cap is opposed to the discharge port formation surface, or by forcibly discharging ink by sucking ink through the discharge port by applying the suction force while the discharge port formation surface is covered with the cap.
In an appropriate position of the apparatus, on the other hand, there is a waste ink tank provided to store waste ink produced by the above-mentioned discharge recovery process.
To lead, into the waste ink tank, the ink received in a discharge recovery apparatus including the cap, pump and waste ink tube communicating these, etc. by the discharge recovery process, a so-called xe2x80x9cidle suctionxe2x80x9d operation, in which the pump is operated while the cap is opened to air, is performed.
This is a very effective operation to prevent remaining waste ink from hardening, and prevent waste ink from leaking outward from the cap when the ink, received within the discharge recovery device by the discharge recovery process, is left to stand alone.
In these processes, however, an amount of ink to be discharged by predischarge, for example, an amount of ink to be discharged by idle discharge or an amount of ink to be exhausted by suction are respectively different because their objectives are respectively different. Nevertheless, an operation of pump means to recover exhausted ink was similar in any of these processes.
In this case, in idle discharge, for example, which is performed by also allowing discharge ports, which are not used, midway during recording to be used for discharging, a duration, in which the recording head remains at a non-recording position, is long. To cope with high speed recording by improving the throughput, it takes a considerable time to maintain and recover, and high speed recording as a whole cannot be accomplished.
Also when a piston type pump was used, ink trapped by an absorber provided within the cap was recovered by repeating the full stroke several times. In this method, however, there were some cases where ink remains in an area far away from the recovery port though ink near the recovery port is well recovered.
In other words, although ink near the recovery port is quickly recovered by driving the piston, ink in an area far away from the recovery port takes time to move to near the recovery port, and cannot fully move only by the suction operationxe2x80x94driving the piston was terminated before the ink moves. As a result, the ink remained in the absorber. Such an existence of such residual ink was likely to cause fixing within the absorber.
Also the number of times for discharge recovery process to be started differs in accordance with frequency in use and product life that vary with the application and the like of the ink jet recording apparatus. In other words, in a recording apparatus with a use application, in which a large amount of waste ink is required, a large capacity of waste ink tank will be required. This is because the volume, which the waste ink tank occupies within the apparatus, becomes larger.
On the other hand, however, miniaturized recording apparatus has been advancing in recent years, and therefore an appropriate ingenuity should be exerted in securing the capacity of the waste ink tank.
Thus, it is an object of the present invention to securely lead waste ink within a discharge recovery apparatus into a waste ink tank by efficiently and securely performing idle suction.
It is also an object of the present invention to perform idle suction which does not deteriorate the throughput during recording.
It is a further object of the present invention to provide an apparatus capable of fully recovering waste ink within a small capacity of waste ink tank by effectively utilizing the space within the apparatus.
It is an object of the present invention to provide a discharge maintaining and recovery apparatus, comprising:
ink receiving means capable of receiving ink which is located opposite to a recording head and comes into contact with said recording head when maintaining and recovering discharge in order to maintain and recover a state of ink discharge from said recording head for discharging ink on a recording medium;
transporting means which connects said ink receiving means to an exhaust ink receiving member for receiving ink exhausted by the discharge maintaining and recovery process, and transports received ink in said ink receiving means into said exhaust ink receiving member; and
control means which performs a first discharge maintaining and recovery process for exhausting ink by means of discharge not concerned in recording by driving said recording head, and a second discharge maintaining and recovery process for exhausting ink by allowing said ink receiving means to come into contact with said recording head and by driving said transporting means, wherein;
said transporting means has more drive in the second discharge maintaining and recovery process than in the first discharge maintaining and recovery process.
It is also an object of the present invention to provide an ink jet recording apparatus, comprising:
a supporting member for supporting said recording head which discharges ink on a recording medium;
ink receiving means capable of receiving ink which is located opposite to a recording head and comes into contact with said recording head when maintaining and recovering discharge in order to maintain and recover a state of ink discharge from said recording head for discharging ink on said recording medium;
transporting means which connects said ink receiving means to an exhaust ink receiving member for receiving ink exhausted by the discharge maintaining and recovery process, and transports received ink in said ink receiving means into said exhaust ink receiving member;
control means which performs a first discharge maintaining and recovery process for exhausting ink by means of discharge not concerned in recording by driving said recording head, and a second discharge maintaining and recovery process for exhausting ink by allowing said ink receiving means to come into contact with said recording head and by driving said transporting means, wherein;
said transporting means has more drive in the second discharge maintaining and recovery process than in the first discharge maintaining and recovery process; and
transporting means for transporting said recording medium.
It is also an object of the present invention to provide a discharge maintaining and recovery apparatus, comprising:
ink receiving means capable of receiving ink which is located opposite to a recording head when maintaining and recovering discharge in order to maintain and recover a state of ink discharge from said recording head for discharging ink on a recording medium; and
pump type transporting means consisting of a piston and cylinder which connects said ink receiving means to an exhaust ink receiving member for receiving ink exhausted by the discharge maintaining and recovery process, and transports received ink in said ink receiving means into said exhaust ink receiving member, wherein;
in said pump type transporting means, the first stroke is different from the last stroke in piston reciprocating motions for a plurality of cycles for leading said exhaust ink into said ink receiving member.
It is also an object of the present invention to provide an ink jet recording apparatus, comprising:
a supporting member for supporting a recording head which discharges ink on a recording medium;
ink receiving means capable of receiving ink which is located opposite to a recording head when maintaining and recovering discharge in order to maintain and recover a state of ink discharge from said recording head for discharging ink on a recording medium;
pump type transporting means consisting of a piston and cylinder which connects said ink receiving means to an exhaust ink receiving member for receiving ink exhausted by the discharge maintaining and recovery process, and transports received ink in said ink receiving means into said exhaust ink receiving member, wherein;
in said pump type transporting means, the first stroke is different from the last stroke in piston reciprocating motions for a plurality of cycles for leading said exhaust ink into said ink receiving member; and
transporting means for transporting said recording medium.
It is also an object of the present invention to provide a discharge maintaining and recovery apparatus, comprising:
ink receiving means capable of receiving ink which is located opposite to a recording head and comes into contact with said recording head when maintaining and recovering discharge in order to maintain and recover a state of ink discharge from said recording head for discharging ink on a recording medium;
pump type transporting means consisting of a piston and cylinder which connects said ink receiving means to an exhaust ink receiving member for receiving ink exhausted by the discharge maintaining and recovery process, and transports received ink in said ink receiving means into said exhaust ink receiving member,
control means which performs a first discharge maintaining and recovery process for exhausting ink by means of discharge not concerned in recording by driving said recording head, and a second discharge maintaining and recovery process for exhausting ink by allowing said ink receiving means to come into contact with said recording head and by driving said transporting means, wherein;
said pump type transporting means controlled by said control means has more drive in the second discharge maintaining and recovery process than in the first discharge maintaining and recovery process, and the first stroke is different from the last stroke in piston reciprocating motions for a plurality of cycles for leading said exhaust ink into said ink receiving member.
It is also an object of the present invention to provide an ink jet recording apparatus, comprising:
supporting member for supporting a recording head which discharges ink on a recording medium;
ink receiving means capable of receiving ink which is located opposite to a recording head and comes into contact with said recording head when maintaining and recovering discharge in order to maintain and recover a state of ink discharge from said recording head for discharging ink on a recording medium;
pump type transporting means consisting of a piston and cylinder which connects said ink receiving means to an exhaust ink receiving member for receiving ink exhausted by the discharge maintaining and recovery process, and transports received ink in said ink receiving means into said exhaust ink receiving member;
control means which performs a first discharge maintaining and recovery process for exhausting ink by means of discharge not concerned in recording by driving said recording head, and a second discharge maintaining and recovery process for exhausting ink by allowing said ink receiving means to come into contact with said recording head and by driving said transporting means, wherein;
said pump type transporting means controlled by said control means has more drive in the second discharge maintaining and recovery process than in the first discharge maintaining and recovery process, and the first stroke is different from the last stroke in piston reciprocating motions for plural times for leading said exhaust ink into said ink receiving member; and
transporting means for transporting said recording medium.
In an ink jet recording apparatus equipped with a recording head for recording by discharging ink on a recording medium, it is also an object of the present invention to provide an ink jet recording apparatus, wherein;
plural waste ink storage members, which receive waste ink to be exhausted by the discharge recovery process in order to maintain at least a state of ink discharge of said recording head in a good condition, are provided by utilizing the empty space within the apparatus.
According to the present invention, it is possible to fully take ink in the pump from the receiving means with less counter-flow by driving the piston for the first several times, and to transport most ink from the pump into the waste ink storage member by driving the piston in full stroke for a final specified number of times.
According to the present invention, since ink, which accumulates in the ink receiving means, is transported into the waste ink receiving member midway during recording for each discharge recovery process (by predischarge) for a specified number of times during recording, the transporting operation is effective. Also an amount of ink, which accumulates in the ink receiving means by predischarge, is less than that during forced exhaust to be performed for recovering the discharge.
Therefore, idle suction during the recording process is performed fewer number of times than a number of times for transporting (idle suction) at the time, and it is effective in improving the throughput of the recording apparatus to reduce the number of times.
According to the present invention, the waste ink receiving capacity increases while the entire apparatus is miniaturized because plural waste ink tanks are installed by utilizing the empty space existing scattered within the ink jet recording apparatus as the space for the waste ink storage member.